[WASM][WinUI][AOT] Build fails

[DierkDroth]

Current behavior

The WASM AOT build fails on my custom WinUI project using VS2022 + .NET6 + latest UNO prelease packages. Turning on diagnostics mode does not show more on the actual cause than this:

3> [00:06:28.3952472] ninja: build stopped: subcommand failed.
3> C:\Users\ddroth.nuget\packages\uno.wasm.bootstrap\3.1.3\build\Uno.Wasm.Bootstrap.targets(175,5): error : System.Exception: Failed to generate AOT layout (More details are available in diagnostics mode or using the MSBuild /bl switch)
3> C:\Users\ddroth.nuget\packages\uno.wasm.bootstrap\3.1.3\build\Uno.Wasm.Bootstrap.targets(175,5): error : at Uno.Wasm.Bootstrap.ShellTask_va01173706452d6a3642c80df957b3b52c781fe91.RunPackager() in D:\a\1\s\src\Uno.Wasm.Bootstrap\ShellTask.cs:line 684
3> C:\Users\ddroth.nuget\packages\uno.wasm.bootstrap\3.1.3\build\Uno.Wasm.Bootstrap.targets(175,5): error : at Uno.Wasm.Bootstrap.ShellTask_va01173706452d6a3642c80df957b3b52c781fe91.Execute() in D:\a\1\s\src\Uno.Wasm.Bootstrap\ShellTask.cs:line 225
3> Done executing task "ShellTask_va01173706452d6a3642c80df957b3b52c781fe91" -- FAILED.

Not sure if relevant, but I have the (unfounded?) suspicion that this problem might be related to the significant size of custom project

Expected behavior

Building WASM AOT should work

[jeromelaban]

To troubleshoot AOT builds, please use the following instructions.

[DierkDroth]

Thanks for your suggestion. However, I didn't help: still same error.

Also:

• I don't have any SkiaSharp in my custom project. So I would have been surprised if that would have made any difference
• I'm only doing standard WindowsAppSDK UI stuff, no additional NuGet packages whatsoever. So I would have been surprised if I had to add lines above which are not needed by the UNO standard template anyway

[jeromelaban]

The SkiaSharp line is a copy paste from the last resolution step of the mentioned issue. Try using the first two lines (v1 and v2).

[DierkDroth]

I just tried that: same problem, AOT fails to build with same error.

Wouldn't the exception stack trace provide any hint on what might be going wrong?

[jeromelaban]

There's likely an error raised by emscripten somewhere in the binlog, for the builddist target. You may search for "error" or "failure" in the outputs for the builddist target.

[DierkDroth]

I followed your suggestions. However, the only error I found (binlog attached) was the exact one which I reported above.

What else could be done to isolate the cause of trouble? Isn't the failing feature part of Uno.Wasm.Bootstrap and as such inspecting the exception callstack could provide us a hint?!?

msbuild.zip

[jeromelaban]

This is the error:

    [00:03:15.3985762] [730/764] [AOT] .\linker-out\Uno.UI.FluentTheme.v2.dll -> ./Uno.UI.FluentTheme.v2.dll.bc.tmp
    [00:03:15.4003194] FAILED: Uno.UI.FluentTheme.v2.dll.bc.tmp 

Make sure that you have set:

<ItemGroup>
	<MonoRuntimeMixedModeExcludedAssembly Include="Uno.UI.FluentTheme.v1" />
	<MonoRuntimeMixedModeExcludedAssembly Include="Uno.UI.FluentTheme.v2" />
</ItemGroup>

in your project.

[DierkDroth]

Thanks @jeromelaban

I tried that before and just tried it again: still same error (see attached). I also attached my project file.

msbuild.zip
Unusual.Wasm.zip

[jeromelaban]

Thanks, FullAOT is not supported in net6 at this time. Use InterpreterAndAOT instead.

[DierkDroth]

Thanks @jeromelaban. That got me going...